The present invention relates to an apparatus for refurbishing belts, more specifically to an apparatus for refurbishing belts having a degraded surface and made out of any material such as a woven or needled fabric with multiple fibers or the like, and to the method for refurbishing the same, the apparatus may be installed as a kit on existing corrugator belt machines or the like.
Corrugator belts are commonly used in corrugated cardboard or papermaker manufacturing machines. They are mainly used as a conveying tool that ensures a uniform pressure on the external sheets of cardboard that are glued or bonded to a central corrugated core to properly and uniformly pull them without relative sliding movement. During this bonding process, relatively high temperatures are encountered and the humidity contained therein needs to escape through the whole surface being bonded and through the belt itself. Such a machine needs to process relatively wide sheets of cardboard to be efficient, as wide as 300 centimeters (118 inches). To that effect, the corrugator belt has to be so manufactured that it would allow humidity to go through over its entire surface. These types of expensive belts are typically made out of a flat-woven or needled multilayer structure fabric embedding a multitude of fibers. After many weeks and months of continuous use, the surface of the belt in contact with the cardboard starts getting dirty and lose efficiency. Also, when smaller width cardboard is processed as opposed to the one covering the full width, the unused edges of the belt are more affected by the overflow of glue or the like that causes non-uniform tearing of the unused surfaces.
This non-uniform tearing of the belt at the edges drastically prevent any further use of that belt with the manufacturing of wider cardboard since the uniform pressure required over the whole surface could not be provided anymore due to edge locally degraded belt surface, without high risks of having to scrap the entire batch of cardboard that would be manufactured in these conditions.
When such a belt becomes so damaged, the cardboard manufacturer needs to discard the used belt and replace it by an expensive new one. To date, nobody has ever come out with a process or an apparatus that would enable a refurbishment or recycling of these discarded used belts by resurfacing the damaged surface so as to provide them with a pristine-like nice and flat surface proper for re-use.
U.S. Pat. Nos. 5,626,447 and 5,882,157 granted to Buysman et al. on May 6, 1997 and Mar. 16, 1999 respectively disclose a belt refurbishing apparatus particularly suited for modular belting formed from universally shaped injection-molded plastic modules, essentially rigid materials, which have generally smooth and impervious surfaces generally used in conveyor systems used for transporting products, especially food products. In such applications of belts, there is no concern about the general flatness of the xe2x80x9cworkingxe2x80x9d surface of the belt as opposed for the belts generally used in paper industry. Also, any cutting device used by Buysman et al. would not be suitable to prevent any fiber tear off damage of the belt during refurbishing of the latter. Also, Buysman et al. do not disclose any means that ensures a proper holding of the belt against the cutting device as required for a non-rigid material belt as well as a push down action of the latter around the cutting device and away from the same. Finally, Buysman et al. do not need to refurbish relatively wide belting since his wide belts typically are formed by modules mounted adjacent to each other, and dismounted whenever required such as for refurbishing, thereby not requiring an accurate uniform thickness removal over the entire belt surface.
It is therefore a general object of the present invention to provide an apparatus for refurbishing belts of the character described which obviates the above noted disadvantages.
An advantage of the present invention is that the apparatus for refurbishing belts is especially suitable for relatively long and wide belts, such as commonly known corrugator belts, that are generally expensive to discard and replace.
A further advantage of the present invention is that the apparatus for refurbishing belts can be assembled as a kit onto an existing belt conveying machine such that the belt can be regularly recycled on-site without removal for optimum overall cost and performance of the machine.
Another advantage of the present invention is that the apparatus for refurbishing belts can remove a determined amount of a degraded surface of the belt independently of the direction of displacement of the latter relative to the grinding member.
A further advantage of the present invention is that the apparatus for refurbishing belts has a grinding member that defines a helical grinding region and a complementary helical nongrinding region thereof to smooth off the grinding operation.
Another object of the present invention is to provide a method for refurbishing belts having a degraded surface that corresponds to the steps performed by the above described apparatus.
According to one aspect of the present invention, there is provided an apparatus for refurbishing a fabric belt, the fabric belt defining a belt width and a generally perpendicular belt length, the fabric belt having a degraded surface, the apparatus comprises:
a frame for partially supporting the fabric belt thereon;
a grinding member including a grinding roller for selectively and uniformly removing a determined amount of the degraded surface along the belt width, the grinding roller defining a generally cylindrical surface and a grinding roller axis substantially parallel to the belt width, the grinding roller rotatably mounting on the frame about the grinding roller axis, the cylindrical surface carrying a grinding device secured thereto, the grinding device defining a generally helical grinding region of the cylindrical surface and a substantially complementary helical non-grinding region thereof;
a driving member secured to the frame for displacing the fabric belt relative to the grinding member along the belt length; and
a positioning member mounted on the fame adjacent the grinding member for positioning the fabric belt adjacent the grinding member during removal of the determined amount of the degraded surface of the fabric belt, the positioning member including:
a belt abutment member spacedly posItioned relative to the grinding member for abuttingly retaining the fabric belt against the grinding member; and
a belt tensioning member for longitudinally tensioning the fabric belt adjacent the grinding roller in the direction of the belt length.
Preferably, the apparatus comprises an adjusting member adjusting the position of the grinding member relative to the belt perpendicularly relative to the belt displacement direction, thereby enabling selection of the determined amount of the degraded surface being removed by the grinding member.
Preferably, the apparatus includes a vacuum cleaning device mounted on the frame adjacent the grinding member and the belt to vacuum particles of the degraded surface removed by the grinding member away therefrom.
Preferably, the apparatus includes a trimming device mounted on the frame for selectively cutting away damaged lateral edges of the belt along the belt length during displacement of the belt relative to the trimming device by the driving member.
Preferably, the trimming device includes:
a trimming lower roller and a generally spacedly opposed trimming upper roller for receiving the belt therebetween, each of the lower and upper rollers defining a corresponding lower and upper roller axis, the lower and upper rollers rotatably mounting on the frame about the respective lower and upper roller axis, the lower and upper roller axes being substantially parallel to the belt width;
an annular-shaped cutter axially slidably mounted on a respective end of one of the lower and upper rollers, the annular-shaped cutters abuttingly contacting the other of the lower and upper rollers so as for trimming the damaged lateral edges of the belt; and
a trimming roller motor selectively actuating rotation of the one of the lower and upper rollers supporting the annular-shaped cutters.
Preferably, the grinding member includes a grinding roller motor selectively actuating rotation of the grinding roller, the grinding roller having a length at least equal to the belt width.
Preferably, the abutment member includes an abutment roller defining an abutment roller axis and a longitudinal apex for abuttingly supporting the fabric belt thereon and having a length at least equal to the belt width, the abutment roller rollably mounting on the frame about the abutment roller axis, the abutment roller being spacedly positioned relative to the grinding roller with the abutment roller axis substantially parallel to the grinding roller axis so as for abuttingly receiving the fabric belt therebetween;
the belt tensioning member includes a tensioning roller positioned on either side of the grinding roller in the direction of the belt length and adjacent thereto, each of the tensioning rollers defining a tensioning roller axis and being rotatably mounted on the frame about the tensioning roller axis, the tensioning roller axes being substantially parallel to the grinding roller axis, each of the tensioning rollers being slidably mounted on the frame and deflecting the fabric belt in a direction generally perpendicular to the degraded surface away from the grinding roller and towards the abutment roller so as to ensure tension within the fabric belt along the belt length adjacent the grinding roller, whereby the fabric belt being in abutment contact with the longitudinal apex of the abutment roller so as to allow the grinding roller to come in contact with the degraded surface of the fabric belt adjacent the longitudinal apex of the abutment roller and grind away the determined amount of the degraded surface therefrom during displacement of the fabric belt relative to the grinding roller.
Preferably, the driving member includes an abutment roller motor selectively actuating rotation of the abutment roller.
Preferably, the positioning member further includes:
a plurality of driving rollers spaced apart from each other along the belt length in the belt displacement direction on either side of the grinding roller, each driving roller defining a respective driving roller axis and rotatably mounting on the frame about the respective driving roller axis, the driving roller axes being substantially parallel to the grinding roller axis, the abutment roller motor selectively actuating rotation of the driving rollers, each of the driving rollers defining a longitudinal apex for abuttingly supporting the belt thereon;
a belt bed mounted on the frame for slidably supporting the belt inbetween respective longitudinal apex of two adjacent of the abutment and driving rollers.
Preferably, the apparatus includes lateral guide members slidably mounted on the belt bed in the direction of the belt width for guiding lateral edges of the belt during its relative displacement thereto.
Preferably, the grinding device is sand paper helically bonded onto the cylindrical surface of the grinding roller.
According to a second aspect of the present invention, there is provided a kit for refurbishing a fabric belt, the fabric belt defining a belt width and a generally perpendicular belt length, the fabric belt having a degraded surface, the fabric belt being installed onto a belt conveyor machine, the kit comprises:
a frame secured to the belt conveyor machine;
a grinding member including a grinding roller for selectively and uniformly removing a determined amount of the degraded surface along the belt width, the grinding roller defining a generally cylindrical surface and a grinding roller axis substantially parallel to the belt width, the grinding roller rotatably mounting on the frame about the grinding roller axis, the cylindrical surface carrying a grinding device secured thereto, the grinding device defining a generally helical grinding region of the cylindrical surface and a substantially complementary helical nongrinding region thereof; and
a positioning member mounted on the frame adjacent the grinding member for positioning the fabric belt adjacent the grinding member during removal of the determined amount of the degraded surface of the fabric belt, the positioning member including:
a belt abutment member spacedly positioned relative to the grinding member for abuttingly retaining the fabric belt against the grinding member, and
a belt tensioning member for longitudinally tensioning the fabric belt adjacent the grinding roller in the direction of the belt length, the belt conveyor machine displacing the fabric belt relative to the grinding member along the belt length.
According to a third aspect of the present invention, there is provided a method for refurbishing a fabric belt, the fabric belt defining a belt width and a generally perpendicular belt length, the fabric belt having a degraded surface, the method comprises the following steps of:
providing a frame for partially supporting the fabric belt thereon;
providing a grinding member, the grinding member including a grinding roller for selectively and uniformly removing a determined amount of the degraded surface along the belt width, the grinding roller defining a generally cylindrical surface and a grinding roller axis substantially parallel to the belt width, the grinding roller rotatably mounting on the frame about the grinding roller axis, the cylindrical surface carrying a grinding device secured thereto, the grinding device defining a generally helical grinding region of the cylindrical surface and a substantially complementary helical non-grinding region thereof;
providing a driving member secured to the frame for displacing the fabric belt relative to the grinding member along the belt length; and
providing a positioning member mounted on the frame adjacent the grinding member for positioning the fabric belt adjacent the grinding member during removal of the determined amount of the degraded surface of the fabric belt, the positioning member including;
a belt abutment member spacedly positioned relative to the grinding member for abuttingly retaining the fabric belt against the grinding member; and
a belt tensioning member for longitudinally tensioning the fabric belt adjacent the grinding roller in the direction of the belt length.